As a sound analysis technique, a mobile communication terminal device disclosed in the below-described Patent Document 1 is conventionally known. This mobile communication terminal device judges, for example, whether a user of the terminal is on a train or in a car, by comparing an environmental noise collected from a microphone to an environmental noise sample that has been registered with the internal portion of the terminal in advance. Then, upon receipt of a telephone call, the mobile communication terminal device plays a response message corresponding to the judgment result.
Also, the below-described Patent Document 2 discloses a call transmission regulation control system for a mobile terminal. This call transmission regulation control system registers a traffic noise with the internal portion of the terminal in advance, and automatically performs a call transmission control if a collected noise matches the registered traffic noise.
Furthermore, the below-described Non-Patent Document 1 discloses a technique for analyzing a sound collected by a wearable device, modeling the behavior of a user, and judging whether the user is working at his/her desk or in a meeting, based on a result of identifying sounds (identifying the typing sound of a keyboard, the flipping sound of paper sheets, and the voices).
The above-described techniques are based on sounds in a living environment. In these techniques, specific individual sounds are identified or classified so as to use applications such as an application for a response message and an application for call transmission regulations and judge a specific situation.
The other prior art documents are described in Patent Documents 3 to 8, which are listed below.    Patent Document 1: Japanese Patent Application Publication No. 2000-209143    Patent Document 2: Japanese Patent Application Publication No. 2004-15571    Patent Document 3: Japanese Patent No. 3607450    Patent Document 4: Japanese Patent No. 3565228    Patent Document 5: Japanese Patent Application Publication No. 2002-142189    Patent Document 6: Japanese Patent Application Publication No. 2000-66691    Patent Document 7: Japanese Patent Application Publication No. 2004-258659    Patent Document 8: Japanese Patent No. 4000171    Non-Patent Document 1: The National Convention of Information Processing Society of Japan in 2006, Vo. 3 “A study of a method for presenting experiential images detectable by behavioral context”.